Apparatus for dyeing, bleaching and other liquid treatment of a material in granular, threaded or fibrous form



2,808,715 APPARATUS FOR DYEING, BLEACHING AND OTHER LIQUID TREATMENT OFduhuZOEdwIF QM mm Jummu PER-GUSTAF MELLGREN Filed April 19, 1955 AMATERIAL IN GRANULAR, THREADED OR FIBROUS FORM Oct. 8. 1957 INVENTORPER-GUSTAF MELLGREN M AVA-Him M.

HIS ATTORNEYS Unite APPARATUS FOR DYEBNG, BLEACHING AND OTHER LIQUIDTREATWNT OF A MATE- RIAL IN GRANULAR, TIREADED OR FI- BROUS FORMPer-Gustaf Mellgren, Avesta, Sweden, assignor to Aktiebolaget Pluria,Stockholm, Sweden, a corporation of Sweden To carry through a dyeingprocess, it is of the utmost importance that it is possible, startingfrom a labile initial state with a maximum concentration of dye in thedyeing bath and with no dye on or in the material to be dyed, to reachin the shortest possible time a final state, in which there is a minimumconcentration of dye in the dyeing bath, and the distribution of dye onor in the material is completely uniform.

This object can be achieved by means of certain known methods which areuseful in bleaching or other liquid treatment and involve a particularmanner of utilizing impregnation in vacuum, by means of which a moreeven and rapid start of the dye fixing process is achieved and a liquidmovement which conforms as closely as possible to the theory andpractice resulting in a more rapid fixation and equalization of thecolour and which comprises frequent reversals of the direction of flowof the dyeing bath (pulsation).

The present invention relates to an apparatus which is particularly wellsuited for the performance of said process in dyeing, bleaching or otherliquid treatment of material in granular, threaded or fibrous form. Inaccordance with the present invention, the apparatus comprises acontainer adapted to confine the material to be treated,

States Patent a vessel in which the treatment liquid is prepared andstored, a pump adapted to operate either as a vacuum pump or as acompressor, and conduit means interconnecting said container, saidvessel and said pumpso that the container may be evacuated, thetreatment liquid may be caused to perform a pulsating movement throughthe material and air may be blown through said container.

The conduit means may be connected to a source of compressed air bymeans of which the treatment liquid may, during the pulsation, besubjected to a constant superatmospheric pressure.

In accordance with this invention it is possible to replace thepulsating movement of the treatment liquid by a heating of the materialto be treated without drying it. For this purpose, the conduit means maybe connected to a steam supply, from which steam admixed with air issupplied to the material impregnated with the treatment liquid.

The invention will be explained in detail below, reference being bad tothe accompanying drawing, which shows diagrammatically an embodiment ofthe apparatus.

As shown on the drawing, the apparatus comprises a container 1 in whichmaterial supports 2 for, e. g., crossed coils of yarn (yarn wound onperforate sleeves) may be placed, e. g. for dyeing, and a closedexpansion vessel 3, in which the treatment liquid (the dyeing bath) isprepared and is heated by means of steam coils 4, e. g. to 110 C. Withthe aid of a pump 5 which is adapted to be used either as a vacuum pumpor as a compressor, the container 1 is evacuated for which purpose avalve 7 in a conduit 6 communicating with the container 1 is opened, afour-way valve 8 is positioned so that comice munication is 'set upbetween the conduit 6 and the conduit 9 wherein the pump 5 is disposedand finally a valve 10 is opened. When the maximum degree of vacuum (e.g. about -95%) is reached in the container 1, the valves 7 and '10 areclosed.

To be able thereupon to subject the entire system to a certain constantsuperatmospheric pressure, e. g. 0.7 kilogram per square cm. aboveatmospheric, a reducing valve 12 in a'pressure conduit 11 is opened andadjusted to the desired superatmospheric pressure. To preventoverloading of the pump 5 when this operates as a compressor, anautomatically operating unloading valve 13 is arranged between thehigh-pressure and low-pressure sides of the compressor, so that asuitable pressure dilference may be maintained between the two sides ofthe compressor. At the same time a valve 15 arranged in a conduit 14between the four-way valve 8 and the vessel 3, is opened. From thismoment, the pump 5 operates as a compressor. Thereupon, a valve 16 isopened, which is disposed in a conduit 17 branched out from a conduit 18connecting the container -1 and vessel 3. Thereby the dyeing liquid willflow from the vessel 3 to the container 1. Since the material to be dyedis usually dry and, due to the evacuation of the container 1, the

a air is removed from all fibres and interstices, a very rapidimpregnation of all pores of the material with dyeing liquid will beobtained. This results in the best possible.

initial state for thesubsequent dyeing process.

When the dyeing liquid in the container 1 covers the material, a valve19 in the conduit 18 is opened and simultaneously the valve 16 isclosed, so that more dyeing liquid from the vessel 3 flows into thecontainer 1 through the conduit 18, until a limit level 20 is reached inthe container 1. At this moment a float-operated non-return valve 21 isautomatically closed, whereby the dyeing liquid in the container 1 isprevented from entering the conduit 6. The valve 7 is now closed and thefour-way valve 8 is operated by means of an impulse transmitting device(not shown) in a manner such that the high-pressure side of thecompressor 5 communicates alternatingly with the container 1 over thevalve 7 and the conduit 6 and with the vessel 3 over the valve 15 andthe conduit 14. Thereby, the dyeing liquid will be caused to pulsatebetween the container 1 and the vessel 3 through the material to bedyed; suitably, this pulsation is carried out so that the dyeing liquidwill always cover the material.

If desired, acertain amount of dyeing liquid may be caused to enter thecontainer 1 without being forced through the material to be dyed. Forthis purpose a valve 22 in a branch conduit 23 may be used. This valve22 suitably consists of a non-return valve so that the dyeing liquid canflow through the valve 22 only in the direction from the vessel 3towards the container 1. Thereby the advantages are obtained that auniform concentra'tion of dye is obtained throughout the dyeing bath,that a greater amount of liquid is circulated through the material in adirection from outside and inwards into the material, whereby theequalization is augmented and further that the liquid level in thecontainer 1 is prevented from being lowered, since the liquid willalways flow more easily from the vessel 3 to the container 1 than in theopposite direction.

After e.,g. 10 to 15 minutes of pulsation the dye is upon, the majorportion of the remaining dyeing liquid in the material is removed byblowing air therethrough. For this purpose, the pump 5 will be made useof, in that after opening the valve 24, air is supplied to the pump 5through a valve'25 and is forced into the container through the four-wayvalve 8, which has been adjusted to the requisite position, and throughthe conduit 6. Thereafter, the container 1 is evacuated in the mannerdescribed above, whereupon rinsing water is introduced via .a .valve 26.

'The rinsing operation may be effectedby evacuating the container 1,filling it with rinsing liquid and draining the material in a repetitivesequence or by allowing the rinsing liquid to flow continuously throughthe materiaL.

If it is desired, during a dyeing process performed at a temperatureabove 100 C., to check the result by opening the container 1, this maybe achieved by forcing the entire dyeing liquid out of the container 1and back to the vessel 3, whereupon the valves 16 and 19 are closed andthe valve 24 opened. Thereby, the pressure and temperature of the liquidremaining in the material are quickly and in a simple manner reduced toatmospheric pressure and 100 C. by vaporization, whereupon the cover ofthe container 1 can be raised.

In certain cases, it may be desirable to cool the dyeing bath. To thisend, cold water can be supplied through the pipe coil 4.

The apparatus shown and described can be used without alteration fornormal bleaching with a circulating, pulsating l a h g liquid.

However, a more rapid and considerably cheaper bleaching operation canbe performed in the same equipment, if e. g. a hydrogen peroxide-waterglass-aqueous caustic soda bleaching liquid is used, and the abovepulsation step is replaced by a rapid and even heating of thebleaching-liquid-impregnated material to be bleached between theabove-described two steps of removal of the major portion of theremaining liquid (in this case bleach ing liquid) from the material bymeans of air and evacuatipn of the container 1. This heating step may beperformed in the following manner:

For about 2 to 4 minutes a mixture of air and steam is blown through thematerial to be bleached at a pressure drop of about 0.1 kg. per sq. cm.For this purpose, steam is introduced through a valved conduit 27 andair through the valve 25. A mixture of air and steam having atemperature of 100 C. and a relative moisture content of about 100% maythus be easily obtained, whereby the material to be bleached will beheated without being dried. The temperatures before and after thecontainer 1 will be checked by means of thermometers 28 and 29. Afterheating the bleaching material the valves '7, 24 and 27 will be closed,and the material will be allowed to remain in the coutainer'i e. g. for40 to 60 minutes. The container 1 is externally heat-insulated, so thatthe ternperature in the material to be bleached remains practicallyunaltered and equal to the predetermined temperature (about 100 C.).After finished bleaching the material may be rinsed as described above.

Having nowparticularly described the nature of my invention and themanner of the operation what I claim is:

1. An apparatus for dyeing, bleaching and other liquid treatment of amaterial in granular, threaded or fibrous form, comprising a closedcontainer to receive the material to be treated, a closed vessel inwhich the treating liquid is prepared and stored, a pump having anintake and a discharge, a four port valve, a first conduit connectingthe upper interior portion of said closed container to one of the portsor" said. valve, a second conduit connecting the upper interior portionof said closed vessel to a second port of said valve, third and fourthconduits connecting the third and fourth ports of said valve to the pumpintake and the pump discharge, respectively, means for operating saidvalve to connect the intake and discharge of said pump selectively tosaid first and second conduits to subject said container to higher andlower pressures than said vessel, other conduits connecting bottominterior portions of said container and said vessel for flow of treatingliquid therebetween, and valves interposed in said other conduitsadjustable to open and closed positions to allow and to prevent,respectively, flow of liquid between said container and said valve, avent valve communicating with said fourth conduit adjustable betweenopen and closed positions, said vent valve enabling said pump towithdraw air from said container and vent it to at least partiallyevacuate said container.

2. An apparatus asset forth in claim 1 comprising a source of compressedgas connected to one of said conduits to introduce gas under pressureinto said container and maintain the treatment liquid at a constantsuperatmospheric pressure.

3. An apparatus as set forth in claim 2 comprising a source of steamconnected to one of said conduits for supplying steam to the liquidimpregnated material.

4. The apparatus set forth in claim 1 comprising means supporting saidmaterial in a position interposed between said other conduits forselective flow of treatment liquid therethroughin opposite directionsand means for actuating said four port valve to alternately connect saidcontainer and vessel with said pump intake and discharge to set uppulsations in the treatment liquid.

5. Anapparatus for treating granular, threaded and fibrous materialswith liquid dye, bleaches and the like comprising a closed containerhaving a hollow support for a material to be treated, a first conduitfor delivering liquid to the interior of said support, said supporthaving means insertable into the material through which liquid isdelivered from said support to the interior of said material, a secondconduit connected to the bottom of said container for supplying saidliquid to the bottom of said container to immerse the material therein,a. third conduit communicating with the'upper portion of said container,a float valve in said third conduit for preventing discharge of saidliquid through said third conduit, a receptacle for treating liquidconnected to said first and second conduits, control valves in saidfirst and second conduits adjustable to open and closed positions, apump having an intake port and a discharge port, a selector valve havingfour ports, a fourth conduit connecting one of said selector valve portsto the upper portion of said receptacle, two ofsaid selector valve portsbeing connected to the intake and discharge ports of said pump,respectively, and the fourth selector valve port being connected to saidthird conduit, said selector valve being adjustable to connect theintake and discharge ports of said pump selectively to said third andfourth conduits to produce selectively (1) a subatmosphere pressure insaid container, (2') different superatmospheric pressures in saidreceptacle and container and ('3) a subatmospheric pressure in saidcontainer and a superatmospheric pressure in said receptacle, and meansfor actuating said selector valve to connect the discharge port of saidpump alternately to said receptacle and said container to alternatelysubject said receptacle to greater and lesser pressures thereby settingup pulsations in said liquid.

6. An apparatus for treating solid materials with liquids comprising aclosed container for receiving the solid material, aclosed receptaclefor treating liquid, conduits connecting the receptacleto saidcontainer, means communicating with one of saidconduits and insertableinto the material and the other of said conduits communicating with theinterior of said receptacle outside of said material, said'. conduitsacting to supply liquid on. opposite sides of said material; in 'saidreceptacle, an air pump having an intake and a discharge, and meansincluding conduits and a selector valve means connecting the intake andthe discharge of said pump to'said container and said receptacle abovethe level of liquid and material therein, said selector valve meansbeing adjustable to connect the intake and discharge of said air pumpselectively to said container and receptacle to produce selectively (1)a subatmospheric pressure in said container and (2) difierent pressuresin said receptacle and container.

References Cited in the file of this patent UNITED STATES PATENTS774,407 Venter Nov. 8, 1904

